Images portrayed on today's video displays, such as CRTs, LCDs and plasma displays, tend to have a defined color gamut and a dynamic range within the standard dynamic range (SDR; sometimes referred to as “low dynamic range” or “LDR”) region.
The term “dynamic range” for an image may refer to a range of an image characteristic (e.g., brightness, luminance) or a ratio of a strongest measure or intensity of that image characteristic to a weakest measure or intensity of that image characteristic. In some cases the weakest measure or intensity of that image characteristic may be noise. In some cases the image characteristic may be luminance, color, a combination of luminance and color, or a function of luminance and/or color. Dynamic range may also be referred to as the ratio between the brightest possible and the dimmest possible, but not black, pixels in an image. This may be subtly different from the contrast ratio, which can be referred to as the ratio between the brightest pixels and black (e.g., off pixels). The human visual system can be capable of over ten orders of magnitude in overall dynamic range, and can have a simultaneously visible dynamic range of around 5 to 6 orders of magnitude. Video displays may have 2 to 3 orders of magnitude in dynamic range.
Color gamut may refer to the space of all colors that can be captured or displayed for a particular device. Video and computer displays may represent colors within a triangle whose vertices are the chromaticity of the red, green, and blue primaries in any of the CIE color diagrams.
Like reference numbers and designations in the various drawings can indicate like elements.